package net;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class TcpEchoServer {
    private ServerSocket serverSocket = null;

    public TcpEchoServer(int port) throws IOException {
        serverSocket = new ServerSocket(port);
    }

    public void start() throws IOException {
        System.out.println("服务器启动！");
        while (true) {
            Socket clientSocket = serverSocket.accept();
            processConnection(clientSocket);
        }
    }

    private void processConnection(Socket clientSocket) throws IOException {
        System.out.printf("[%s:%d] 客户端建立连接！\n", clientSocket.getInetAddress().toString(), clientSocket.getPort());
        try (InputStream inputStream = clientSocket.getInputStream()) {
            try (OutputStream outputStream = clientSocket.getOutputStream()) {
                Scanner scanner = new Scanner(inputStream);
                while (true) {
                    if (!scanner.hasNext()) {
                        System.out.printf("[%s:%d] 客户端断开连接\n", clientSocket.getInetAddress().toString(), clientSocket.getPort());
                        break;
                    }
                    String request = scanner.next();
                    String response = process(request);
                    PrintWriter writer = new PrintWriter(outputStream);
                    writer.println(response);
                    writer.flush();
                    System.out.printf("[%s:%d] req: %s,resp: %s\n", clientSocket.getInetAddress().toString(), clientSocket.getPort(), request, response);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            clientSocket.close();
        }
    }

    private String process(String request) {
        return request;
    }

    public static void main(String[] args) throws IOException {
        TcpEchoServer tcpEchoServer = new TcpEchoServer(9090);
        tcpEchoServer.start();
    }

}
